# Reservoir engineering using quantum optimal control for qubit reset

@article{Basilewitsch2019ReservoirEU, title={Reservoir engineering using quantum optimal control for qubit reset}, author={Daniel Basilewitsch and Francesco I. Cosco and Nicolino Lo Gullo and Mikko M{\"o}tt{\"o}nen and Tapio Ala-Nissil{\"a} and Christiane P. Koch and Sabrina Maniscalco}, journal={New Journal of Physics}, year={2019}, volume={21} }

We determine how to optimally reset a superconducting qubit which interacts with a thermal environment in such a way that the coupling strength is tunable. Describing the system in terms of a time-local master equation with time-dependent decay rates and using quantum optimal control theory, we identify temporal shapes of tunable level splittings which maximize the efficiency of the reset protocol in terms of duration and error. Time-dependent level splittings imply a modification of the system…

## 14 Citations

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## References

SHOWING 1-10 OF 87 REFERENCES

Optimal control of a qubit coupled to a non-Markovian environment.

- PhysicsPhysical review letters
- 2009

This work systematically search for optimal pulses using a generalization of the novel open systems gradient ascent pulse engineering algorithm to investigate the implementation of quantum gates for a paradigmatic, non-Markovian model: a single-qubit coupled to a two-level system that is exposed to a heat bath.

Efficient protocol for qubit initialization with a tunable environment

- Physics
- 2016

We propose an efficient qubit initialization protocol based on a dissipative environment that can be dynamically adjusted. Here, the qubit is coupled to a thermal bath through a tunable harmonic…

Stabilizing Entanglement via Symmetry-Selective Bath Engineering in Superconducting Qubits.

- PhysicsPhysical review letters
- 2016

D dissipative stabilization of entanglement between two superconducting transmon qubits is demonstrated in a symmetry-selective manner and suppression of the Bell state of opposite symmetry due to parity selection rules is demonstrated.

Beating the limits with initial correlations

- Physics
- 2017

Fast and reliable reset of a qubit is a key prerequisite for any quantum technology. For real world open quantum systems undergoing non-Markovian dynamics, reset implies not only purification, but in…

Time-optimal control of the purification of a qubit in contact with a structured environment

- PhysicsPhysical Review A
- 2019

We investigate the time-optimal control of the purification of a qubit interacting with a structured environment, consisting of a strongly coupled two-level defect in interaction with a thermal bath.…

Quantum harmonic oscillator state synthesis by reservoir engineering

- PhysicsScience
- 2015

The mechanical motion of a single trapped ion is used to generate squeezed, coherent, and displaced-squeezed states as steady states in the presence of noise to facilitate studies of entanglement, quantum computation, and open-system quantum simulations in a wide range of physical systems.

Fast and Unconditional All-Microwave Reset of a Superconducting Qubit.

- PhysicsPhysical review letters
- 2018

This work experimentally demonstrates a reset scheme for a three-level transmon artificial atom coupled to a large bandwidth resonator that has no additional architectural requirements beyond those needed for fast and efficient single-shot readout of transmons, and does not require feedback.

Training Schrödinger’s cat: quantum optimal control

- Physics
- 2015

In this communication, state-of-the-art quantum control techniques are reviewed and put into perspective by a consortium of experts in optimal control theory and applications to spectroscopy, imaging, as well as quantum dynamics of closed and open systems.

Resonator reset in circuit QED by optimal control for large open quantum systems

- Physics, Computer Science
- 2017

This implementation of the open GRAPE (Gradient Ascent Pulse Engineering) algorithm, well suited for large open quantum systems, avoids explicit matrix exponential calculations leading to a polynomial speed-up, as well as the reduced memory requirements of this implementation.

Steady-state entanglement of two superconducting qubits engineered by dissipation

- Physics
- 2013

We present a scheme for the dissipative preparation of an entangled steady state of two superconducting qubits in a circuit quantum electrodynamics (QED) setup. Combining resonator photon loss—a…